Preventing Adolescent Cannabis Use through Web-Based Graphic Warning Imagery

Sally Rooke1, Jan Copeland1& Don Hine 2 1National Cannabis Prevention and Information Centre – 22-32 King St., Randwick NSW, 2031

2School of Cognitive, Behavioural and Social Sciences, University of New England, Armidale NSW, 2351

Acknowledgements

This research was funded by Australian Rotary Health.

Conclusions •Findings provide support for further testing of the effectiveness of web-delivered warning imagery in deterring adolescent cannabis use.

•Graphic images of physical health outcomes may be more effective than images of negative social and mental health outcomes.

Aim The objectives of this study were to: • Develop and pilot test an automated web-based cannabis prevention program employing warning imagery. • Determine which kinds of images are likely to be most effective.

We tested the hypothesis that adolescents exposed to the intervention would report significantly greater reductions in cannabis use following the six-month intervention period than would a control group of adolescents not exposed to the intervention.

Introduction A national Australian survey conducted in 2009 found that 5.5% of 14-17 year olds reported cigarette smoking in the last year compared to 13% reporting cannabis use in this time period (AIHW, 2010). Reductions in cigarette use may be due to increased awareness of the dangers of tobacco smoking, brought about through extensive public health campaigns, such as mandated graphic warning imagery. Previous research suggests that warning imagery has strong potential to deter adolescent substance use.

Method Participants

156 adolescents aged 14-18 were recruited into the study.

The study employed a cluster randomised design. Students from two private schools and one Technical and Further Education (TAFE) centre were randomly assigned to the intervention condition (n = 88), and students from two private schools and one TAFE were randomly assigned to an assessment only condition (n= 68).

Intervention

The intervention group received 13 automatically generated emails, sent fortnightly, containing links to graphic and emotion provoking warning images about cannabis use. Each warning contained (a) a graphic or otherwise emotion provoking image; (b) a brief factual statement relating to the image; and (c) more detailed information written below the main statement in smaller text. Images addressed potential social, mental and physical health effects of cannabis. All warnings had been associated with cannabis use in at least one study.

Measures

•Basic demographic information (age and gender).

•Ever tried cannabis? •Past-month and past week frequency •Past-week quantity •Intervention group: Effectiveness rating out of 10 for each

image.

Procedure

All participants were sent an initial email containing a link to the assessment questions. Participants in the intervention group were then sent an automatically generated email each fortnight, containing a different warning image. Participants in the control group received no further contact from us until the post-intervention assessment. All participants were sent an automatically generated email containing a link to the post-intervention assessment six months after completing the baseline assessment.

Results Results

Cannabis Use

Very few adolescents in either group used cannabis.

Participants in the intervention group reduced their past month (t (121) = 2.31, p = .02) and past week (t (121) = 1.90, p = .03, 1 tailed) frequency of cannabis use, as well as their past week quantity of cannabis use (t (121) = 1.71, p = .047, 1 tailed), significantly more than did participants in the control group.

There was a 30.5% reduction of participants reporting use in the past month in the control group compared with a 66.3% reduction in the experimental group.

No participant in either group reported cannabis use initiation during the course of the study.

Images

A brief description and average rating for each warning is provided in Table 2. Negative social and mental health effects generally received low ratings of effectiveness as cannabis use deterrents, whereas graphic images of physical health effects received higher ratings.

A brief description and average rating for each warning is provided in Table 2. Negative social and mental health effects generally received low ratings of effectiveness as cannabis use deterrents, whereas graphic images of physical health effects received higher ratings.